I wanted to mention about the bolded, while that is usually true, it is not always so. My ds lost speech at age one and has been severely delayed until recently(age 9). And he is still somewhat delayed.
He is incredibly smart, but processes things differently, has sensory issues, has no emotional response control(he is doing SO MUCH better with this lately), does not "get" social cues, add a little adhd and ocd in there and that about sums it up, lol.
But I would not change anything about him

yes, yes, and yes!!!

My oldest is Aspie (he is 5)this is a modified list - there are lots more, just can't think as i'm at work

*side note: he had major digestive issues from the start*

Birth-12mon
was able to do puzzles before the age of 1yr
lots of sensory issues
had words
repeated things over and over
did not want to be touched

12mon-2yrs
Continued sensory issues
Quirks
No eye contact
“investigating” items
Understand of abstract, but not normal
lost words

2yrs-3yrs
Lost words – started with ECI (early childhood intervention)
ECI, noted quirks & differences
Quirks became more ”interesting”
Change in routine was not allowed
Got upset/meltdowns in stores & traffic
Hyper sensory to motorcycles, lawn mowers, vacuums (he would literally try to become one with the couch)
Started understanding complex situations, but wasn’t able to understand the simple tasks
Lined/stacked – EVERYTHING ( you couldn’t move it)

3yrs-4yrs
SENSORY!!!
Gained most of his words back
Repeated you
No eye contact
Doesn’t know personal space
Doesn’t pick up on cues
Still advancing in some areas, while is delayed in others

3 1/2yrs old - Got diagnosed under 2 different medical teams (both with the same diagnosis) as:
Hypo/Seeking SPD
Mild-Autism with possibility of Asperger’s with x/y/z therapy

He started at a full time therapy center (5days) when he was 3 1/2yrs old

He still have sensory things (he flips to hyper/seeking during the fall/winter months and then flips back to hypo/seeking in the spring/summer months)
He processes that of an 10yr old, but still is delayed in “typical milestone areas”
Minimal (2-5sec)/no eye contact
Brain doesn’t shut down at night
Still needs a rigid plan of events
Speaks faster than his mind can keep up